One of the simplest methods of recording and communicating information is the traditional method of writing the information down on a piece of paper with a writing instrument such as a pen. Writing information by hand on a piece of paper is inexpensive and can be done quickly and easily with little preparation. The traditional method is also flexible in that a writer can generally write in any format anywhere on the page. One of the limitations with handwritten work is that it is not easily manipulated or transferred to other contexts. In other words, changing or transferring a piece of handwritten text typically requires rewriting the text on another medium.
With the widespread use of personal computers, textual information often is recorded using word processing software running on a personal computer. The advantage of such electronic methods of recording information is that the information can be easily stored and transferred to other remote computing devices and electronic media. Such electronically recorded text can also be easily corrected, modified, and manipulated in a variety of different ways.
Typical computer systems, especially computer systems using graphical user interface (GUI) systems such as Microsoft WINDOWS, are optimized for accepting user input from one or more discrete input devices. Common input devices include a keyboard for entering text and a pointing device, such as a mouse with one or more buttons, for controlling the user interface. The keyboard and mouse interface facilitates creation and modification of electronic documents including text, spreadsheets, database fields, drawings, and photos.
One of the limitations with conventional GUI systems is that a user must generally type the text they are entering into the personal computer using the keyboard. Entering text using a keyboard is generally slower and more cumbersome than handwriting. Although recent advances have been made in reducing the size of personal computers, they are still not as portable and easily accessible as traditional paper and pen. Furthermore, traditional pen and paper provide the user with considerable flexibility for editing a document, recording notes in the margin, and drawing figures and shapes. In some instances, a user may prefer to use a pen to mark-up a document rather than review the document on-screen because of the ability to freely make notes outside of the confines of the keyboard and mouse interface.
To address the shortcomings of traditional keyboard and mouse interfaces, there have been various attempts to create an electronic tablet that can record handwriting. Such electronic tablets typically comprise a screen and a handheld device that is similar to a pen. A user can write with the handheld device on the screen of the electronic tablet in a similar manner to traditional pen and paper. The electronic tablet can “read” the strokes of the user's handwriting with the handheld device and recreate the handwriting in electronic form on the screen with “electronic ink”. This electronic table approach can be employed in a variety of ways, including a personal computer and a handheld computing device.
Recently, other computer systems have been developed that provide for more sophisticated creation and manipulation of electronic ink. For example, the Microsoft READER application permits one to add electronic ink to a document. The system stores the ink and provides it a user when requested. Other applications (for example, drawing applications associated with the Palm and PocketPC operating systems) permit the capture and storage of drawings. These drawings include other properties associated with ink strokes used to make up the drawings. For instance, line width and color may be stored with the ink. One goal of these systems is to replicated the look and feel of physical ink being applied to a piece of paper. However, physical ink on paper can have significant amounts of information not captured by the electronic collection of coordinates and connecting line segments. Some of this information may include the thickness of the pen tip used (as seen through the width of the physical ink), the shape of the pen tip, and the speed at which the ink was deposited.
In spite of the advances in electronic tablets and electronic ink, there are still several limitations with the performance of such electronic handwriting devices. One of those limitations concerns the ability to quickly and accurately edit electronic handwriting. Conventional approaches to editing handwriting strokes on an electronic tablet are limited in that a user cannot quickly and easily identify a portion of a word or drawing for erasing or editing. The conventional method is further limited in that a user is often unsure about which handwriting strokes of the word or drawing have been selected for editing until the edit is actually made.
In view of the foregoing, there is a need in the art for a system and method that allows a user to quickly and accurately edit electronic ink. Specifically, there is a need for an editing function that provides feedback to the user concerning the handwriting strokes that are selected for editing. The feedback element of the editing function should be visual, such as shading the handwriting strokes that have been selected before they are edited. The feedback component must be precise so that a user can edit a handwriting stroke that is a portion of a word or drawing. The feedback capability should also allow the user to edit relatively large amounts of text expeditiously. It is further desirable for an editing function to recognize handwriting gestures associated with editing. In other words, the editing function should be able to recognize certain gestures made by the user and associate them with particular handwriting strokes. For example, a “strikethrough” gesture, such as a single or multiple line cross-out, can be associated with a particular handwritten word that it to be edited. The editing function should also provide the user with options to select, modify, or delete handwriting strokes associated with an editing gesture.